Starter190-ORSUBSORT · znzryb

## 思路讲解

codeChef题目可以看viewsolution，就是下面这个链接

```cpp
inline ll diff(ll a,ll b){
	if(a<=b) return 0;
	bitset<32> ba(a);		// 存储是正序的
	bitset<32> bb(b);
	ROF(i,31,0){
		ll bai=ba[i],bbi=bb[i];
		if(bai-bbi==1){
			return 1<<i;
		}
	}
}
```

## AC代码

[https://www.codechef.com/viewsolution/1165814370](https://www.codechef.com/viewsolution/1165814370)



::: 源代码

```cpp
// Problem: Subsequence Sort
// Contest: CodeChef - START190
// URL: https://www.codechef.com/problems/ORSUBSORT
// Memory Limit: 256 MB
// Time Limit: 1000 ms
// 
// Powered by CP Editor (https://cpeditor.org)

#include <bits/stdc++.h>
#define all(vec) vec.begin(),vec.end()
#define CLR(i,a) memset(i,a,sizeof(i))
#define fi first
#define se second
#define pb push_back
#define SZ(a) ((int) a.size())
#define FOR(i, a, b) for (int i = (a); i <= (b); ++i)
#define ROF(i, a, b) for (int i = (a); i >= (b); --i)
#define debug(var) cerr << #var <<":"<<var<<"\n";
#define lson(var) (var<<1)
#define rson(var) ((var<<1)+1)

using namespace std;

typedef long long ll;typedef unsigned long long ull;
typedef double DB;typedef long double LD;
typedef __int128 i128;typedef pair<DB,DB> pdd;typedef pair<ll,bool> plb;
typedef pair<ll,ll> pll;
typedef array<ll,3> arr3;typedef array<ll,2> arr2;
constexpr ll MAXN=static_cast<ll>(1e6)+10,INF=static_cast<ll>(1e9)+9; // 1e18+9也是素数
constexpr ll mod=static_cast<ll>(1e9)+7;
constexpr double eps=1e-8;

ll N,M,Q,X,K,lT,A[MAXN];
/*

*/
inline void init(){
	
}
inline ll diff(ll a,ll b){
	if(a<=b) return 0;
	bitset<32> ba(a);		// 存储是正序的
	bitset<32> bb(b);
	ROF(i,31,0){
		ll bai=ba[i],bbi=bb[i];
		if(bai-bbi==1){
			return 1<<i;
		}
	}
}
inline void solve(){
	cin>>N;
	init();
	FOR(i,1,N){
		cin>>A[i];
	}
	bool isSort=true;
	FOR(i,2,N){
		if(A[i-1]>A[i]){isSort=false;break;}
	}
	if(isSort){cout<<0<<"\n";return;}
	ll mxD=0,mx=A[1];
	FOR(i,2,N){
		mxD=max(mxD,diff(mx,A[i]));
		mx=max(mx,A[i]);
	}
	cout<<mxD<<"\n";
}

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);cout.tie(0);
	cin>>lT;
	while(lT--){
		solve();
	}
	// solve();
	return 0;
}
/*
AC
https://www.codechef.com/viewsolution/1165814370
*/
```


:::


## 心路历程（WA，TLE，MLE……）